PRK
Photorefractive Keratectomy (PRK) involves using the excimer laser to remove a very thin amount of tissue from the surface of the cornea. This slight change in shape is all that is required to compensate for most focus problems. Currently the excimer laser can be used to treat nearsightedness, astigmatism, and nearsightedness with astigmatism. The FDA has not yet approved PRK for use on farsightedness.